Method and apparatus for combustion



May, 24, 193s. M, FRISCH 2,118,600

METHOD ND APPARATUS FOR COMBUSTION ATTORNEY.

May 24, 1938. M. FRlscH METHOD AND APPARATUS FOR COMBUSTIQN s'sheets-sneet 2 Filed Jan. 21, 1955 www , INVENTQR. Agn/v /Ck/Jcf/ ATTORNEY.

May 24, 1938. M. FRIsCH 2,118,600

METHOD AND APPARATUS FOR COMBUSTION Filed Jan. 21, 1935 5 Sheets-Sheet 5 nwENToR.

Mawr/N HP/Jcff ATTORNEY.

May 24,1938. l M FmscH u 2,118,600

ME-THOD AND APPARATUS FOR COMBUSTION Filed Jan.. 2l, 1935 5 Sheets-Sheet 4 INV ENTOR.

ATTORNEY.

May 24, 1938. M. FRlscH METHOD AN APPARATUS FOR COMBUSTIO 5 Sheets-Skiset 5 Filed Jan. 2l,4 1935 ATTORNEY.

PatentedMay24,1938

' UNITED sTATEs 'METHOD AND srrm'rus ma coMnUs'rroN Martin Frisch. Cranford, N. J., aaaignor Foster Wheeler Corporation. New York, N. Y a corporation of New York application January 21, lass, sensi Nn. am

13Clalms.

This invention relates to the combustion of fuels and provides novel methods and apparatus for producing the combustion of fuels entrained in currents or streamsof air.

The invention is capable ofenective application to the burning of a wide variety of fuels but is particularly useful for the combustion of pulverized fuels of low volatility. With low volatile fuels. auch as certain anthracite and bituminous coals. it is desirable that the ratio of fuel to the carrying air which is delivered to the furnace by the burners be high so that ignition may be easily produced and maintained and it is also desirable that thc velocity oi' the air fuel mixture delivered by the burners be low for the reason that the velocity of flame propagation'of such mixtures is ordinarily very low. A

The methods and apparatus of the present invention readily and emciently effect the controll o! the richness of a fuel and air mixture which is delivered to fuel burners from the source of sup. f

ply to provide the degree of richness of the mixture which is delivered by the burners to the furnace for eillcient combustion. 'Ihe invention also provides an effective control of the velocity at which the combustible mixture of desired richness is delivered by the burners to the furnace. Other features and advantages of the invention will be perceived from the following description considered in connection with the accompanying drawings, forming a part thereof, in which the embodiments of the invention which have been selected for disclosure are illustrated.

In the drawings:

Fig. 1 is a view in elevation with parts in section. of apparatus for producing combustion which embodies the present invention;

Hg. 2 is a front elevational view of the apparatus shown in Fig. l:

Fig. 3 is a sectional elevational view on an enlarged scale of the burner shown in Fig. 1;

Fig. 4 is a transverse sectional view taken on line 4-4 of Fig. 3:

Pig. 5 is a sectional view taken on line 5 5 of Fig. d; 4

Fig. 6 is a sectional view taken on line 6-6 of Pls. 5:

Fig. 'l is a sectional view taken on line 'l-l of Hg. 3;

l'lmisasectionalvicw takenonlinet--tof Hs. 1:

Fig. 9 is a view in elevation with parts in section. of another form of apparatus embodying the invention:

Fig. 14 is a sectional view taken on line Il-Il 10 of Fig. 13; and

Fig. 15 is asectional view taken on line Il-IB of Fig. 11.

Like characters of reference designate the same or similar parts in the several views of the drawl5 ings.

'I'he forms of the invention disclosed are arranged for producing combustion in the furnace of steam generating apparatus but it will be understood that the invention is not limited to this particular application but may be employed for producing combustion in any other furnace.

Referring particularly to Figs. 1 to 8 inclusive.

reference fcharacter .2l designates the furnace of a steam generator having a setting 2| and a 25 steamand water drum 22. The steam generator may be of any desired form. 'Ihe system disclosed in these gures of the drawings effects the reduction oi' the fuel to nely divided form,

the entraining of the reducedfuel in a current of air and the delivery of the fuel and air mixture directly to the furnace by means of burners embodying the invention'. The fuel. anthracite or bituminous coal in this instance, is delivered to the feed pipes Il and isconducted through the fuel feed portion oi' a classifier 24 into the pulverizing mill 25 of any suitable type. The mill comprises a rotatable drum having pulverizlng means such as a plurality of steel balls of varying diameters. troduced into the mill through the air inlet I9 and sweeps entirely through the mill over the surface oi the fuel being pulverized therein and picks up the reduced fuel and carries it through the classifier 24 wherein the fuel particles which 45 have not been sui'iiciently pulverized are separated from the fuel and air stream and are. returned to the mill 2l. The air stream and entrained pulverized fuel then flows through discharge pipe Il into an exhauster 21 which is 5o driven by suitable means such as the electric motor Il. A damper Il is hingedly mounted in pipe 28 and is movable between a position in which pipe 2i is fully open and an opening il is completely closed and a position in which pipe 55 Air. preferably preheated. is in- 40 position intermediate these two positions to close or open to varying degrees the opening Il in pipe 2l and at the same time to operate as a control valve for pipe 2G. Damper |1 may be operated manually or automatically. The exhauster 21 delivers the fuel and air mixture into a distributor 28 which distributes the mixture more or less uniformly to the delivery pipes 2l which conduct the fuel and air mixture to burners Il which embody the invention.

The burners 3|! are arranged to discharge vertically downwardly through burner ports 3| in a horizontally disposed wall 32 of the boiler setting 2|. Suitable means indicated 33 are provided for supporting the burners 3l in proper position relative to the ports 3|. Referring particularly to Figs. 3 to 6 inclusive, each burner 3U comprises a pair of contiguous cylindrical casings 3l having open lower ends with a centrifugal separator 35 disposed in its upper portion, a nozzle 3B in its lower portion and a tubular member 31 which is gradually contracted toward its lower end and which connects the separator and the nozzle. The upper ends of members 31 are welded or otherwise secured to the interior of.

the casings 34 and the lower ends 38 are threaded for connection to the upper ends of the nozzles 36. The lower ends of the cylindrical casings 34 fit into cylindrical apertures in a member 3S which engages the setting 2| and the walls of ports 3|, and the upper ends of the casings are closed and held together by a cover lll. The fuel and air mixture is delivered through pipe 29 in a vertically downward direction into an elbow Il through which it is delivered in a horizontal direction to the separators 35 through adjacently disposed inlet ports I2 in the walls of caslngs Il. The stream of fuel and air delivered to the burners is divided by the vertically disposed edges I3 of the casings 3l at the contiguous sides of ports 42, into two approximately equal portions, each of which is caused to ow in a spiral path toward the nozzles 36 in the annular s'pace I6 between the casing 3l and the tubular outlet I3 which extends downwardly from the cover I and is coaxially disposed in the upper part of the casing 34. A portion of the stream of fuel and air ilowing through each separator 35 is continually withdrawn through the outlet l! and is delivered through the connection 5l to a delivery pipe Il which may conduct the separated air and any fuel entrained therein to any point desired. In this instance, the separated air and fuel is delivered to the furnace as part of the secondary air supply as will hereinafter be described. Thethe casings 3l, provide means for rotating the nozzles 36 about their axes with respect to members 31 so that the fuel and air jets delivered by the nozzles may be directed as desired to impinge upon each other or not as desired. Means are provided for throttling the upper ends of the nomles 36 in order to provide for the control of y the degree to which the fuel and air mixture delivered to the separators is enriched and also to.

control the velocity at which the enriched fuel and air mixture is delivered by the nozzles to the furnace. In this instance, such means consists of vertically reciprocable valves 5l which may be described as consisting of two frusta-conical sections with a common base. .-valves are mounted adjacent the lower ends of valve rods il which extend upwardly through the members 31 and separator outlets 48 and are supported in tubular supports 6l on member 5U. 'Ihe upper end of each of the valve rods 53 is provided with an operating handle 62 and that portion of each valve rod which lies in the zone of and adjacent to the support SII is provided with a series of small apertures 6I through which a pin 65 may be inserted to retain the valve and the rod in the desired adjusted position. The lower end of each valve rod 5B is provided with a suitable guiding member I6 which engages the innercylindrical surface of the upper end of nozzle4 3Q to maintain the coaxial relationship between the nozzle and the valve. As shown, the maximum diameter of the valves 56 is smaller than the inside diameter oi' the upper ends of the nomles 36 so that the nozzles are never completely closed by these valves. The cylindrical casings 3l are each provided with openings in their central portions in the zones of the members 31, through which secondary air may be introduced into the furnace at the burner nozzles through the space 61 between the casing 34 and the members 31 and nozzles 33. These openings are closed by hinged doors Bl provided with means for clamping them in adjusted position which comprises a lever 69 fixed at one end to the door and having a threaded member 1li secured to its other end which moves in an arcuate slot in a plate 1I secured to casing 3l. A nut lll' on the end of an operating handle provides the clamping action" required. Each burner is provided with an ignition opening in member 39 adjacent the nozzles 3i, which is closed by a hinged cover 1|.

The lean mixture or the portion of the air and the fuel entrained therein which is separated from the main or original mixture in each burner, is delivered by the pipes 5| through ports 12 in the wall 13 of the setting 2|. The discharge end 14 of each pipe 5| is provided with a valve 15 which may be a check valve or may be controiled 'by .suitable means depending upon the circumstances oi' operation. An air casing 16 spaced from the walls of the setting 2|; provides a passageway 11 through which air is delivered to the furnace through a plurality of secondary air ports 1l. These ports 13 are controlled by valves 19 which are supported on and are operated by valve rods III. Each of these rods lll has an arm Il fixed to its outer end which is pivotally connected to an operating rod 82. Rod 82 is vertically or axially reciprocated by a hand wheel 83 threaded to the upper end of the rod... An indicator Il on the upper end of rod I2 provides means by which the extent to which the ports 12 are opened may be visually determined.

The operation is as follows: A mixture of primary air and pulverized fuel entrained therein is withdrawn from mill and after passing through the classier 2l is withdrawn through pipe 26 by the exhauster 21 and is delivered to the distributor 2l which more or less uniformly distributes the mixture to the several pipes 29 through which the mixture is delivered to the separators 35 of the burners 3l. In flowing downu' wardly in a spiral path through the annular spaces I8 of the separators 8l. the greater portion of the pulverized fuel is thrown toward the outer peripheral portions of the streams ortoward the casings 8l and upon reaching the lower ends of the outlets 48, portions of the moving air streams together with relatively small portions of the finer particles of the entrained fuel are withdrawn through the outlets 48 and flow through the pipes 8| and are discharged through ports 12 into the lower part of the furnace to support the combustion of the fuel. 'I'he withdrawal of portions of the lair and fuel streams flowing through the separators 88 is due to the suction action on the furnace 28 by a stack or an induced draft fan connected thereto and to the throttling action of valves 58 which Acontrol the burner nozzles 88. The enriched mixture of fuel` and air ilows downwardly through members I1 from the separators 88 into the nozzles 88 and is discharged thereby into the furnace 28 where it is burned. Tl'ie velocity at which the enriched primary air and fuel mixture is discharged into the furnace is determined by the positions of valves 88, or in other words, is determined by the extent to which the inlet ends ofthe nozzles 88 are opened or closed by these valves. the extent to which the mixture of primary air and fuel is enriched since they control the difference in pressure between the nozzle inlets and the separator outlets I8. Secondary air in the volumes necessary for combustion may be introduced through the secondary air inlet ports in the burners which are controlled by doors 88 and through the ports 18 in the side walls of the furnace.

With this arrangement it will be perceived that fuels of low volatility may be satisfactorily and efficiently burnedfor the reason that the velocity at which the primary lair and fuel mixture is delivered to the furnace by the burners may be readily and accurately controlled and the ratio of fuel to air in the air fuel mixture delivered to the furnace by the burners may also be readily and accurately controlled. Economy in operation is effected'by this arrangement since the air and fuel. mixture which is separated from the main fuel and air stream, is delivered to the furnace to support combustion. The range of the control effected by this arrangement may be illustrated from the following: The rich mixture or concentrate delivered to the furnace by the burners may contain from 15 to 35% of the original primary air which is delivered to the burner mixed with from 65 to 90% of the fuel delivered to the burner.v The lean mixture separated fom the main stream of primary air and fuel and which is delivered to some point in the furnace outside of the ignition zone of the enriched mixture or to any other desired point, will contain from to 65% of the air in the original stream which is delivered to the burners and from 10 to 35% of the fuel originally delivered to the burners.

Another arrangement embodying the invention is illustrated in Figs. 9 and 18. In this arrangement'. a diflerentV form of separator is employed which is disposed at some distance from the burners. 'I'he separator indicated 88 has an inlet 88 connected to the discharge end of a pipe 29 which conducts the primary air and fuel mixture from the distributor 28. 'Ihe inlet 88 of the separator is connected to inlets 81 and 88 of similar 4but oppositely arranged separator casings 89 and 98, respectively, both of which are arranged to provide spiral paths of flow Il of the fuel and air These valves also control mixture therethrough. Centrifugal force acting streams causes them to be more or less concentrated in the outer peripheral portions` of the streams thereby enriching these portions which pass through a plurality of spaced bame plates 82 and thence through outlets 98 and 9|, respectively, into and throughpipes 98 to the burners 88 which may be of any suitable form or design. Portions of the air streams flowing through the spiral flow paths 9| are withdrawn through outlets 91 and 98 respectively, and are delivered through pipes 99 to the furnace 28 adjacent the burners 98 or to any other point in the furnace, or to any point outside of, or remote from, the furnace 28. At the point at which the fuel and air mixture is delivered to the inlets l1 and 88 by pipe 88, 'switching valve |88 is provided so that the burner 9 8 connected with either .of the pipes 88 may be shut down without disturbing the operation of the other. Valve |88 is doublefaced and self rseating and is movable about 'a pivot |8I by any suitable operating means into and out of engagement with seats |82 and |88 in inlets 81 and 88 respectively. A shield |84 in inlet 88 protects the valve from the abrasive action of the fuel when both inlets 81 and 88 are fully open, at which time the valve |88 is positioned in vertical alignment with the shield |84. Valves |28 similar to the'valve 15, are provided for the pipes 99. Valves |28 may be of the check type or may be controlled by suitable means to control the extent to which the fuel and air mixture which is delivered to the burners, is enriched.

A further arrangement embodying the invention is shown in Figs. 1l to 15 inclusive. In this arrangement the fuel and air mixture is delivered through pipes 29 to elbows A4| through which it is delivered to two adjacently disposed burners |85 and |88. Each of these burners comprises an upper cylindrical portion |81, an intermediate portion |88 of gradually restricted flow area downwardly, a lower cylindrical portion |89 having a distributing cone ||8 closing its lower end and nozzles and I2 connected at their upper ends to the portion |88, at diametrically opposed points as may be seen from Fig. 14 particularly. I'he nozzles have a rectangular flow area in this instance and nozzle I|2 is directed vertically downwardly while nozzle is directed in a vertically inclined direction toward the nozzle ||2. 'I'he arrangement is such that the fuel and air liets discharged from the nozzles do not impinge upon each other. The lower portions of the outer side walls ||8 and |14 of the nozzles and I2 respectively, are removable and are hinged at their upper ends Ill and I6 respectively to the nozzles to provide regulating valves for the nozzles to control the velocity at which the enriched fuel and air mixture is discharged into the furnace and also to provide a control for the degree to which the original mixture delivered to the burners is enriched. The upper portion |81 of the burners acts as a separator and the separated portions of the air and entrained fuel are withdrawn through outlets ||1 and are delivered through a pipe ||8 to the pipes Il. In view of the foregoing description of the operation of the burners disclosed in Figs. 1 to 8, the operation of this form of burner will be apparent.

It will be perceived that the methods and apparatus disclosed will effect the combustion of fuels under the most favorable conditions so that eillcient burning is provided for fuels of varying degrees of volatility. The fuel in finely divided or pulverized form is delivered from the source of supply to the burners entrained in air of sumcient quantity to carry the fuel to the burners. Prior to the injection of the fuel into the furnace for combustion, the original fuel and air mixture is enriched to the extent desired for the most eiilcient burning of the fuel and the velocity at which the enriched mixture is delivered to the furnace is controlled to provide the most emcient burning from the standpoint of flame Drollagation.

Although a so-called unit system has been disclosed wherein the fuel is delivered to the burners directly from the pulverizing equipment, it will be understood that the fuel may be delivered to the burners from any other source of supply such as a storage bin.

Since changes may be made in the form, lo-

cation and arrangement of the several parts of theembodiments of the invention herein disclosed without departing from the invention, it will be understood that I do not intend to limit the invention except by the scope of the appended claims.

What I claim is:

1. The method of producing combustion of 10W volatile fuels which comprises entraining the fuel in a stream of air, separating part of the air from said stream thereby enriching the remaining fuel and air mixture, delivering the enriched mixture to a. furnace for combustion in an ignition zone and delivering the separated air to the furnace outside said ignition zone to support combustion of the enriched mixture.

2. The method of supplying pulverized fuel to a furnace for combustion which comprises entraining the fuel ln a stream of air, delivering the fuel and air mixture to a separating zone, separating part of the air from said stream thereby enriching the remaining mixture,l delivering the enriched mixture to the furnace for combustion in an ignition zone and delivering the separated air to the furnace outside said ignition zone to support combustion of the enriched mixture.

3. Apparatus for producing combustion of low volatile fuel in a furnace comprising a burner, means for supplying fuel suspended in a stream of air to the burner, means for withdrawing part of the air from said stream to thereby enrich the remaining fuel and air mixture, means for delivering the enriched mixture to the furnace for combustion in an ignition section thereof, and means for delivering the air withdrawn from the stream to the furnace outside said ignition section to support combustion of the enriched mixture.

4. The method of producing combustion of low volatile fuels which comprises entraining the fuel in a stream of air, causing said fuel and air stream to flow into a separating zone, separating part of the air from said stream thereby enriching the remaining fuel and air mixture to an cx- `tent that ignition may be easily produced and maintained, delivering the enriched mixture in a vertically downward direction to the furnace for combustion in an ignition zone, and delivering the separated'air to the furnace outside said ignition zone to support combustion of the enriched mixture.

5. The method of producing combustion of low volatile fuels which comprises entraining the fuel in a stream of air, causing said fuel and air stream to flow in a curved path, withdrawing part ofthe air from the fuel and air stream as it flows through the curved path to enrich the remaining mixture to an extent that it .may be readily ignited, delivering the enriched mixture to a furnace for combustion in an ignition zone, controlling the degree to which said remaining mixture is enriched, and delivering the separated air to the furnace outside said ignition zone to support combustion of th enriched mixture.

6. 'Ihe method of producing combustion of low volatile fuels which comprises entraining the fuel in a stream of air, causing said fuel and air stream to flow in a curved path, withdrawing part of the air from the fuel and air stream as it iiows through the curved path to enrich the remaining mixture to an extent that it may be readily ignited, delivering in a vertically downward direction the enriched mixture to a furnace for combustion in an ignition zone, controlling th'e degree to which said remaining mixture is enriched, and delivering the separated air to the furnace outside said ignition zone to support combustion of the enriched mixture.

7. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream of air to a separator, means for withdrawing part of the air from said mixture to thereby enrich the remaining mixture to an extent that it can be readily ignited, a burner nozzle through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

8. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a' stream of air to a separator, means for withdrawing part of the air from said mixture to thereby enrich the remaining mixture to an extent that it can be readily ignited, a burner nozzle through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, said nozzle being disposed so that the enriched mixture flows therethrough by the action of gravity, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

9. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream of air to a separator, means for withdrawing part of the air from said mixture to thereby enrich the remaining mixture to an extent'that it can be readily ignited, a burner nozzle through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, a valve for controlling the nozzle to thereby control the degree to which the mixture is enriched, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

10. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream of air to a separator, means for withdrawing part of the air from said mixture to thereby enrich the remaining mixture to anextent that it can be readily ignited, a burner nozzle through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof,

saidnozzlebeingdisposedsothattheenriched mixture ows therethrough by the action of gravity, -a valve for controlling the nozzle to thereby control the degree to which the mixture is enriched, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

11. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream of air to a separator, means for withdrawing part of the air from said mixture to thereby enrich the remaining mixture to an extent that it can be readily ignited, a plurality of nozzles through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, a valve for controlling the iiow area of each nozzle to control the degree to which said mixture is enriched. and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

l2. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream of air to a separator, means for withdrawing part ot the air from said mixture to thereby enrich the remaining mixture to an extent that it can be readily ignited, a plurality of nozzles through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, one of the walls of each of said nozzles being movable to control the degree to which said mixture is enriched, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

13. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream -of air to a separator, means for withdrawing part of the air from said mixture to thereby enrich the remaining mixture to an extent that it can be readily ignited, a burner nozzle through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, one of the Walls of said nozzle being movable to control the flow area of said nozzle to control the degree to which said remaining mixture is enriched, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

MARTIN FRISCH.

DISCLAIMER 2,118,600.Martin Frisch, Cranford, N. J.

` 24, 1938. Disclaimer filed January 12,

eler Corporation.

BUs'rIoN. Patent dated Ma 1940, by the ass1gnee, Foster METHOD AND APPARATUS Foa CoM- Hereby enters this disclaimer to claims 1 to 10 inclusive of the above identified [Qical Gazette February 6, 1.940.]

patent.

mixture ows therethrough by the action of gravity, -a valve for controlling the nozzle to thereby control the degree to which the mixture is enriched, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

11. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream of air to a separator, means for withdrawing part of the air from said mixture to thereby enrich the remaining mixture to an extent that it can be readily ignited, a plurality of nozzles through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, a valve for controlling the iiow area of each nozzle to control the degree to which said mixture is enriched. and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

l2. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream of air to a separator, means for withdrawing part ot the air from said mixture to thereby enrich the remaining mixture to an extent that it can be readily ignited, a plurality of nozzles through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, one of the walls of each of said nozzles being movable to control the degree to which said mixture is enriched, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

13. Apparatus for producing combustion of low volatile fuel in a furnace comprising means for supplying the fuel entrained in a stream -of air to a separator, means for withdrawing part of the air from said mixture to thereby enrich the remaining mixture to an extent that it can be readily ignited, a burner nozzle through which the enriched mixture is delivered to the furnace for combustion in an ignition section thereof, one of the Walls of said nozzle being movable to control the flow area of said nozzle to control the degree to which said remaining mixture is enriched, and means for delivering the air withdrawn from said mixture to the furnace outside said ignition section to support combustion of said enriched mixture.

MARTIN FRISCH.

DISCLAIMER 2,118,600.Martin Frisch, Cranford, N. J.

` 24, 1938. Disclaimer filed January 12,

eler Corporation.

BUs'rIoN. Patent dated Ma 1940, by the ass1gnee, Foster METHOD AND APPARATUS Foa CoM- Hereby enters this disclaimer to claims 1 to 10 inclusive of the above identified [Qical Gazette February 6, 1.940.]

patent. 

